Total noob, I know.
I know you can use it to hack games, but that's about all. (I'm trying to hack Animal Crossing: City Folk.)
Thanks for any info...
homebrew refers to a collection of programs that we run without Nintendo's consent. You need to soft-mod your Wii to use it. Look at wiibrew.org, and google "bootmii" and "bannerbomb".
Without a USB Gecko, you can't *hack* games per se, but you can use the codes that hackers make by using a homebrew app called Gecko OS.